7721 datasheet(38/577 Pages) RENESAS

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CENTRAL PROCESSING UNIT (CPU)

7721 Group User’s Manual

2–15

2.3 Access space

Figure 2.3.1 shows the M37721’s access space.

By combination of the program counter (PC), which is 16 bits of structure, and the program bank register

(PG), a 16-Mbyte space from addresses 016 to FFFFFF16 can be accessed. For details about access of an

external area, refer to “CHAPTER 3. CONNECTION WITH EXTERNAL DEVICES.”

The memory and I/O devices are assigned in the same access space. Accordingly, it is possible to perform

transfer and arithmetic operations using the same instructions without discrimination of the memory from

I/O devices.

Fig. 2.3.1 M37721’s access space

: Indicates the memory assignment

of the internal areas.

: Indicates that nothing is assigned.

Note : Memory assignment of internal RAM area varies according to the type of microcomputer.

This figure shows the case of the M37721S2BFP.

Refer to “Figure 2.4.1” for the M37721S1BFP.

SFR : Special Function Register

00000016

00008016

00FFFF16

01000016

FE000016

FF000016

FFFFFF16

SFR area

Internal RAM area

Bank 016

SFR area

02000016

00047F16

00007F16

Bank 116

Bank FF16

Bank FE16

001FC016

001FFF16

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